72506410381 has 4 divisors (see below), whose sum is σ = 74466043132. Its totient is φ = 70546777632.

The previous prime is 72506410367. The next prime is 72506410393. The reversal of 72506410381 is 18301460527.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 33163687881 + 39342722500 = 182109^2 + 198350^2 .

It is a cyclic number.

It is not a de Polignac number, because 72506410381 - 2⁵ = 72506410349 is a prime.

It is a super-2 number, since 2×72506410381² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 1959632713 = 72506410381 / (7 + 2 + 5 + 0 + 6 + 4 + 1 + 0 + 3 + 8 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 72506410381.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72506411381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 979816320 + ... + 979816393.

It is an arithmetic number, because the mean of its divisors is an integer number (18616510783).

Almost surely, 2^72506410381 is an apocalyptic number.

It is an amenable number.

72506410381 is a deficient number, since it is larger than the sum of its proper divisors (1959632751).

72506410381 is a wasteful number, since it uses less digits than its factorization.

72506410381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1959632750.

The product of its (nonzero) digits is 40320, while the sum is 37.

The spelling of 72506410381 in words is "seventy-two billion, five hundred six million, four hundred ten thousand, three hundred eighty-one".